How to Balance a Central Heating System (UK)
Set lockshield valves to equalise flow across all rads. Cures rooms hot near boiler, cold far away.
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Why balance?
Nearest rads get most flow — furthest starve. Correct balance = even ΔT (11 K) across every rad.
Procedure
All rads on max. Boiler up to temp. Feel each flow and return; use pipe thermometer for accuracy. Close lockshield on hot rads by 1/4 turn increments until ΔT equalises at ~11 K flow-to-return.
Frequently asked questions
- Which rad should I open fully?
- Furthest from the boiler — always fully open. Close nearest rads progressively to match.
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